1. Field of the Invention
The present invention relates to an image superimposing apparatus and, more particularly, to an image superimposing apparatus for superimposing a digital image signal with an external video signal in synchronization.
The instant application is based on Korean Patent Application Nos. 94-35080, 94-35083, 94-35084 and 94-35345, which are incorporated herein by reference for all purposes.
2. Brief Discussion of Related Art
In an image superimposing apparatus such as a video-song accompaniment apparatus, song lyrics are superimposed on an image signal, i.e., a background screen, while the apparatus is reproducing a musical accompaniment signal. In such an apparatus, to facilitate background screen selection, either digital image information prerecorded on recording media or image information supplied from an external video source may be selected as the background screen. To enable such selection, synchronization and level-matching of the video signals should be realized. When superimposing the external analog video signal and the video signal reproduced from digital image data, if the synchronization is not performed correctly, distortion of the screen image occurs.